This file is not needed to be stored in git at all, remove it.
It will be added during publishing process by CI scripts and is only
needed for publishing to docs.openstack.org.
Add doc/build to gitignore file so that no new content will be checked
Add api/autoindex.rst to toctree to fix build.
Add usual build_sphinx stanza to setup.cfg so that building and
publishing in OpenStack CI works. These parameter are crucial.
Moved what were called unit tests to the functional directory as there is
more work to be done to make them self supporting.
Added sphinx to the test-requirements along with testr deps.
Adjusted the tox.ini to suit.
Added doc source tree with the minimal set of files to allow sphinx
The metric filter allows metrics to be filtered before aggregation,
for example to exclude metrics from certain environments or nodes
from being included where they are outside the scope of data
aggregation. This is a powerful feature but not appropriate for
all scenarios (e.g. devstack). So default the filter to empty.